A Malaysian university has come under fire for holding a contest to "convert" gay students.

The contest at Universiti Sains Malaysia on the island of Penang urged students to create videos and posters as part of a campaign called "Back to Nature".

Members of the Muslim Students Association, which organised the contest, said being LGBT is bad for your health "like smoking".

Activists on Wednesday warned the competition could drive people in the Muslim-majority country to suicide.

The winning entries of the contest, held last month, were a video with drawings of a LGBT person who started to change after meeting a religious friend, and a poster calling for gay people to "return to the path of Allah".

A member of the Muslim Students Association, Amirah Sulaiman, 22, said the campaign was a "soft approach" to turn LGBT community members back to the "natural path".

"We will work hard to convert them," she said.

"LGBT is like smoking - it is bad for health.

"We want to be close to LGBT people and influence them via Islam."

Homosexuality is condemned in Malaysian society, with colonial-era criminal bans on sodomy still in place, with punishments of up to 20 years in prison, caning or a fine.

Thilaga Sulathireh, founder of transgender rights group Justice for Sisters, said the contest could cause serious damage.

"It can cause harm, such as anxiety, depression and suicide attempts," she said.

"There must be more programmes with facts to educate people about (the LGBT community)."

The controversial competition comes nearly a year after Malaysian health authorities were forced to shut down plans for a contest to "prevent" homosexuality.